Leather stitcher presser foot control



22, 1944; E. G.. woLF 2,355,293

LEATHER STITCHER PRESSER FOOT CONTROL original Filed July 17, 1939 2 shets-sheet `1 E. G. woLF LEATHER STITGHER PRESSER FOOT CONTROL I Aug, 22, 1944.

original Filed July 17. 1959 2 sheets-shed 2v EUGENE G. WoLF BY a HTTaQ/vf" l Patented Aug. 22, 1944 LEATHER s TlTonER' PRESS-En FOOT CONTROL Eugene. (L Wolf, S.t\..I.1.ous,1V Lo-, assigner .to Landis.-

Machine Company, St. Louis, Mo., a corporation of Missouri` Griginall application July 1-7, 1939, Serial No.

284,8:1-9; now-Patent No. 2,273,080, dated February. 17;.1942. Divided andi this. application Octoberv 4, 1.9.41., Serial No..4-13;,5.8.31.

(CL. Ilz-61) 10i claims.

The invention relates to sewing rnachineslandr particularly: the typeA of leather stitchersl usedy in sewing shoe. soles anduppers together, and the invention consists in-structuretor effecting and releasing. a presser foot lock andY applyingthe presser foot to the work.

Y The presentl application is adivision-of an ap-V plioation` lledy by. the present inventor July 17, 1939, Serial No. 284,819, now Patent No.` 2,273-,- 080, issued Februaryl'l, 19.42.

It is'customary in machinesA of vthis'typevto--usea, spring to thrust thepresser foot towards the work at all. times and to use a cam-actuated device toflock thepresserfootin-work-gripping position to holdk the4 Work rmlyagainst movement over the work support during-the= greater part of the machine cycle but this deviceis released'for a short period during each cycleto permit thework tofbe fed, thel length of the stitclfi-forwtheT succeeding operation.

TheA device may be connected to the presser foot by a ratchet and pawl device, theratchet teeth being intended to accommodateva-riations in the thickness of the work; Obviously; the" work may be ofA athickness -intermediate sucoessive* ratchetteeth andV obviously Wear on the; ratchet teeth and the-point*ofthe ratchet pawltend to make thefsecurelocking-of theg-worlibythe presserA foot imper-manentA even thoughV thel ratchetA and pawl device-were-eiective initiallyl for agivensetting.

Inanother construction, the presser foot may.

be operatedby a plurality'of, camactuated devices, one of which operates thejadjustmentilock and the other of which operates the positive thrust onthepresser foot;

The main objectof'the present'invention isto;` l

simplify-the constructionl forv actuatingv aH presser footlock, as indicated,- whichwill besecure irre. spective of: the thicknessof the work; andi which will remain secure irrespective offwear inthe. It: isvfurther -desired to construct the lock parts. parts sothey willlvrequire little space thereby facilitating..v assembly and replacement and also increasing the accessibility of adjacentmeeha` nisms.

Itis a further objectof -theinvention-to provide-g a manual release for-thev-locking structure whereby the presser foot mayybereleasedatany time"` in the cycle ofl operationseof; the machine irrespective of the positionofthe-machine cam which- These and other detailed-clogl ec-tsof Athe invention- -as will appear'from the-followingdescription are attained by the structurey illustrated in. the. accompanying drawings in which?.-

Figure 1 is aside elevation of. a shoe. stitcher of the typereferred to, some ofthe parts being broken away to more clearly illustrate the mech-` anism. The presserfoot lock` is shown` in functioning position.

Figure 2- isa detail section and elevationlook ing in the same direction and showing thepress er foot released by itsy cam on the-main-shaft of the Y machine.`

Figure-3` is asimilar view showingV the presser foot releasedfby the manual control*independent-V lyof the presser foot camon thermain shaftj Aside from the novel presser foot control, they machine corresponds to the Goodyear type off stitchers familiar to those skilledin the'art-and includes a pedestal I, a table or-head 2 having brackets 3gjournalling the main cam shaft 4: B indicates the work supportv bracket onwhich the shoe sole S rests. The operating.' endsof' the usual'curved a wl andneedle arev shownat I3 andil I4' respectively and oscillate about a' common.

axis A in the usual manner.

Thepresser foot is formedon the forwardend. of an arm I6. which is moved about a fixedi axisl I5an1jin the normal operation-of the machina.

the. action of the presser foot iscontrolledby. thel cam groove I0 in cam discv 9 through roller. II on. The inner end I'I ofj arm I6" is.

cam lever I2; pivotally connected toa forkedjaW I8f-0n a rod I9' slidably mounted in, a sleeve 20 which, in.. turnis slidable in amember 2l havingjaxed] againstthe work. The lower end of sleevef'Zllterminates in a jaw 23.

threaded portion of therod has a corrugated cylindrical exterior and is rotatablein a dog 25: seatedin jaw 23, when the 4dog isi-inY the positionn shown in Figures 2 and 3..Y But if thedogfbe.

tilted so that the axis of. its openingisdisposed angularly. to the axis oi' `rod.I9,' as shown-inqllig-v.. ure 1, nut24`is held against rotationeinthe. dog-y I9 is heldv against axial movementfv and rod through the` dog and the sleeve.

A. disc 26has anintegral lateral vstud`.2..'l projecting from itsiar side and journalledinlthe lower endrof the depending Aarmon'camlever I2 `and theperiphery of disc 26`is recessedor chan- A spring 32, seated von the upperend of sleeve 20, thrusts thepresser foot,

The. lower end .Of-rod, I 9 has l a steep. square thread, andy a, nut; 2li` onf the--` nelled to receive a roller 28. A shouldered pin 41 -is mounted on the near side of disc 26 eccentrically of its axis, the small diameter portion of the pin extending across the channel in the disc and journalling the roller 28. The large diameter portion of pin 41 projects from disc 26 so that the disc may be rotated about its axis by a manually operated element 45 (Figure 3), as del scribed below. Throughout the major portion of the cycle o'f operations cam groove I I) holds lever I2 in the position shown in Figure 1 and roller 23.tilts dog 25 to the position shown in Figure 1," holding nut A24 against rotation and therefore holding rod I9 against axial movement.

During a short period in the cycle of operations of the machine the restricted high portion Illa of the cam depresses cam lever I2, disc 26 and roller 28 (see Figure 2), thereby unlocking the presser foot but leaving it subject to the thrust of spring 32. Under this thrust the work may be moved across the work support bracket B by the usual feeding mechanism (not shown) Preferably elements ID, I2, 26 and 28 are so arranged that when the parts are in the position shown in Figure 1, dog 25 will not only be tilted about the axis of rod I9 to hold the nut locked against rotation and thereby hold rod I9 against movement through sleeve 29, but the dog, rod and sleevewill be moved as a unit upwardly a slightdistance from the position shown in Figure 2 to thrust the presser foot into tighter engagement with the work than provided by spring 32. The extent of this movement is controlled by screw 30, the adjustment of which will vary the relation between the unit (sleeve 28, jaw 23, dog) and roller 2S. If screw 30 is adjusted downwardly in plate 29, from the position shown inFigure 2, sleeve 2IJ, jaw 23 and dog 25 will be raised and more of the roller upward movement will be required to tilt the dog to lock the nut before the dog, rod and sleeve are moved as a unit to positively thrust the presser foot against the workin addition to the spring thrust. Vice versa, if screw 30 is adjusted upwardly in plate 29, from the position shown in Figure 2, the sleeve, jaw and dog will be lowered relative to roller 28 and a smaller portion of the roller lift will be required to tilt the dog to lock the nut to the rod and a greater portion of the roller lift will move the dog, sleeve and rod as a unit; hence the pressure `o-n the work will -be increased.

Manually operated mechanism is provided for releasing the presser foot lock at any time in the cycle of operations of the machine. This mechanism comprises a rod connected at its lower end to a foot treadle (not shown) and at its upper end to a lever 36 pivoted to a shaft 31 journalled in the machine head and connected by a link 38 to a bar 39 slidable vertically in gibsk (not shown) on the machine frame. The left hand face of bar 39 has an offset track 4I engaging the opposing face of an arm 42 pivoted at 43. A lug 44 on arm 42 (Fig. 3) engages the right hand end of a lever 45 pivoted on pin 22 and the left hand end of the lever engages pin 41 on disc 26 aligned with `the journal of roller 28 but at the outer side of the disc nearest the eye.

When the treadle and rod 35 are depressed, slide 39 moves downwardly to the position shown in Figure 3 in which it thrusts arm 42 to the left, the thrust being transmitted through lever 45 to pin 41 which rotates disc 26 about its axis 21 and against the pull of spring 48 to move roller 28 to'the position shown in Figure 3 in which the tail of dog 25 is freed from roller 28, vwhich has been holding the dog tilted, to release nut 24 and permit it to be rotated by movement therethrough of rod I9 irrespective of the position of cam groove I0, lever I2 and disc pivot 21. Thereupon hook 49 on bar 39 engages pin 40 on the presser foot arm to tilt the same about its pivot I5 and lift the presser foot from the work,

rod I9 moving downwardly and its threads'rothose illustrated and described herein and the, exclusive use of such modications as come with.

tating nut 24.free1y in dog 25.

Spring (Figure l) returns the treadle rod and all the parts actuated thereby to normal position whenever pressure on the treadle is released.

The presser foot manual control is associated with the manual control of the thread lock 56, which is also cam actuated in the normal operavtion of the machine through another groove 6 in the cam disc, lever 8, and connections from the latter to the thread lock which are detailed and described in the above-mentioned earlier led application.

The construction provides a positive lock for the presser foot for any given thickness of work and does not depend upon the proper spacing of a series of ratchet teeth relative to the presser foot and work-supporting bracket as is required in the ratchet type locks previously used as illustrated, for example, in Patent 1,921,277 issued to the present applicant.

With spring actuated or ratchet actuated presser foot locks as previously used, it has been customary to adjust the locking elements every couple weeks or so to maintain their effectiveness, thereas machines with the present locking structure have been run without adjustment for a period of -six months.

It will be noted that a single cam actuated device locks the presser foot against movement -because of the yielding of its spring 32 and also positively applies pressure in addition to the spring pressure, as may be required to grip the work rmly.

A It will be understood that the presser foot lock described herein may be used independently of the thread lock although the preferred arrangement contemplates the use of both of these locks in association with each other, and their manual release by a common mechanism.

The principles of the invention may be embodied in structures differing in details from in the scope of the claimsV is contemplated.

What is claimed is:

` 1. In a stitching machine, a presser foot, means; for holding said presser foot against the work; including a thrust-transmitting rod, a nut; threaded thereon, and a tiltable dog surrounding; said nut and holding it against rotation when;

tilted, a cam, a member actuated thereby, an;

element movable on said member to engage said,

dogl so that said cam may tilt said dog to hold` said nut against rotation and to shift said nut, rod and'presser foot as a unit to tightly grip the work.

2. In a stitching machine, 'a presser foot, means for holding said presser foot against the work including a thrust-transmitting rod, a nut threaded thereon, and a tiltable dog surrounding said nut and holding it against rotation when tilted, a cam, a member actuated thereby and including a portion movable towards and away fromY said dog, an element movably mounted on said member to be shifted into position to oppose said dogand to tiltthe same as the cam moves said,

portion toward said dog, a spring thrusting said element into dog-opposing position, a part for moving said element out of said position against the thrust of said spring, and manually operable means for so moving said part and for then moving said presser foot away from the work.

3. In a stitching machine, a sleeve, a rod slidable but non-rotatable in said sleeve, a nut threaded on said rod and rotatable but non-slidable in said sleeve, a dog carried by said sleeve and associated with said nut and shiftable to position to hold the nut against rotation, a cam and a cam actuated part for shifting said dog to said position, and a presser foot arm actuated by said rod, said part, sleeve, dog, nut and rod being movable as a unit to apply positive pressure on the work through the presser foot.

4. A machine as described in claim 3 in which a spring is provided between the sleeve and the rod normally thrusting the rod to move the presser foot towards the work.

5. A machine as described in claim 1 which also includes a manually operable device having a part for moving the dog engaging element away from the dog to free the nut and having a part for shifting the presser foot away from the work.

6. A structure as described in claim 1 which includes a manually operable device movable at any time in the cycle of the cam irrespective of the position of the cam actuated member and the dog engaging element and having parts disposed to engage the presser foot and the dog engaging element to disengage the latter and to lift the presser foot from the work.

7. In a stitching machine having a drive shaft,

a presser foot member, an arm carrying the same, a reciprocable rod connected thereto, a substantially stationary mounting member adjacent said rod, a jaw movably supported by said member, a nut threaded on said rod, a dog surrounding said nut and supported by said jaw and tiltable on the latter to different positions to accommodate the rotation of the nut on the rod or to hold the nut against rotation, a cam on said shaft, and a lever actuated by said cam for tilting said dog and lifting it and said jaw, whereby the rod may be gripped and moved positively to tightly clamp the work irrespective of the thickness of the work.

8. In a presser foot mechanism for a stitching machine having a drive shaft and a work support, a reciprocating rod operatively connected to the presser foot, a sleeve slidably receiving said rod and having opposing jaw elements facing 1ongitudinally of the axis of the rod and sleeve, a substantially stationary member slidably receiving said sleeve, opposed seats on said rod and sleeve, a spring compressed between said seats and thrusting the rod and presser foot towards the work and thrusting the sleeve through said member, means on said member and sleeve limiting the movement of the sleeve under the thrust of said spring, a nut threaded on said rod and positioned between said jaw elements, a device movable to different positions to accommodate or prevent rotation of the nut on the rod, a cam on said shaft, and means actuated -by said cam during a portion only of the cycle of operations of the machine to move the device to lock the nut against rotation on the rod and to positively thrust the presser foot against the work.

9. A machine as described in claim 8 which also includes a member operable manually at will to engage the device moving means to release the nut from the device.

10. Structure as described in claim 8 in which the means limiting the movement of the sleeve under the thrust of the spring includes an adjustable part to vary the relative movement of the sleeve and the member receiving it and thereby controls the movement of the presser foot towards the work.

EUGENE G. WOLF. 

